ponytail

He says nothing. He writes one line. It works.

An agent skill that stops your AI from over-building. Two hooks, one command.

npm install -g @0xwilliamortiz/ponytail-improved
ponytail

_{claude code · codex · copilot cli · opencode · github}

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What this is

You know him. Long ponytail, oval glasses, at the company longer than the version control. You show him fifty lines and he says nothing, then replaces them with one.

Ponytail puts him inside your AI agent. It ships as skills plus two lifecycle hooks, so before the agent writes code it has to justify writing any at all.

How it works

Before writing code, the agent goes down the ladder and stops at the first rung that holds.

  1 does this need to exist? → no. skip it. (yagni)
  2 is it already in this repo? → reuse it
  3 does the stdlib do it? → use it
  4 does the platform do it? → use it
  5 does an installed dep do it? → use it
  6 can it be one line? → write the line
  ──────────────────────────────────────────────────────────────
  7 nothing above held → the minimum that works

The ladder runs after the problem is understood, never instead of understanding it. Lazy about the solution, thorough about reading.

Note

Lazy, not negligent. Validation, error handling, security and accessibility never go on the chopping block. The 100% figure below is that promise, measured.

Before and after

You ask for a date picker.

your agent	ponytail
3 files	1 line
50 lines	<input type="date">
1 dependency
1 open thread about timezones	the browser already had one

Numbers

Measured over real Claude Code sessions on a real repository. On the tasks where agents over-build hardest, the drop reaches 94% less code.

Full writeup

Install

npm install -g @0xwilliamortiz/ponytail-improved
ponytail

Or without a global install:

npx @0xwilliamortiz/ponytail-improved

From a local checkout:

npm install -g .
ponytail

ponytail prints install commands for your agent. On Windows it can also open the UI.

Works with

Claude Code · Codex · Copilot CLI · OpenCode · Pi · Antigravity · Hermes · OpenClaw · and more

The plugins run two small Node lifecycle hooks, so node has to be on your PATH. Without it the skills still load, and the always-on activation simply stays quiet.

Commands

Command	What it does
/ponytail [lite | full | ultra | off]	Set the intensity, or turn it off
/ponytail-review	Review the current diff for over-engineering
/ponytail-audit	Audit the whole repo, not just the diff
/ponytail-debt	Collect the shortcuts you deferred into a ledger
/ponytail-help	Quick reference

FAQ

What if I really need the 120-line cache class?

You don't. Insist anyway and he builds it. Slowly. Correctly. While looking at you.

Does this make the agent worse at hard problems?

The ladder decides how much to build, not how much to think. Rung 7 exists for the cases where nothing simpler holds, and the guards above are never traded away for brevity.

Why "ponytail"?

You know exactly why.

License

MIT. The shortest license that works.

_{He says nothing. He writes one line. It works.}